On Intel Broxton the GPIO hardware consists of several chips that all share
the parent interrupt. It is not possible to handle this by setting chained
handler for each chip (as they will overwrite each other).

To overcome this we need to request the interrupt using devm_request_irq()
and pass IRQF_SHARED with the flags.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>